Treprostinil derivatives and compositions and uses thereof

ABSTRACT

The present disclosure provides treprostinil derivatives that can act as prodrugs of treprostinil. The treprostinil derivatives can be used to treat any conditions responsive to treatment with treprostinil, including pulmonary hypertension, such as pulmonary arterial hypertension.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims priority to andthe benefit of U.S. application Ser. No. 14/742,544 filed on Jun. 17,2015, whose entire disclosure is incorporated herein by reference forall purposes.

BACKGROUND OF THE DISCLOSURE

Pulmonary hypertension (PH), which includes pulmonary arterialhypertension (PAH), is a disease that can result in death and ischaracterized by increased pulmonary artery pressure and pulmonaryvascular resistance. Some drugs that can be used to treat PH or PAHcannot be effectively administered orally for various reasons and aregenerally administered via subcutaneous, intravenous or intramuscularroutes. These routes of administration generally require intervention bya healthcare professional, and can entail considerable discomfort aswell as potential local trauma to the patient.

One example of such a drug is treprostinil. Treprostinil as the freeacid has an absolute oral bioavailability of less than 10% and a veryshort systemic half-life due to significant metabolism. Treprostinil canbe administered in an inhaled form, but about 50% of PAH patients cannottake inhaled treprostinil due to irritation. Treprostinil (also calledCompound A herein) has the following structure:

Treprostinil can exist as a salt, such as a sodium or diethanolaminesalt.

SUMMARY OF THE DISCLOSURE

The present disclosure describes treprostinil derivatives that can actas prodrugs and provide increased systemic availability of treprostinil.In some embodiments, treprostinil derivatives have the structure ofFormula (I):

wherein R¹ and R² independently are hydrogen,

and R³, R⁴, R⁵, R⁶, j and m are as described herein, or pharmaceuticallyacceptable salts, solvates, hydrates, clathrates, polymorphs orstereoisomers thereof, with the proviso that:

both R¹ and R² are not hydrogen;

neither —OR¹ nor —OR² forms an acetate;

neither —OR¹ nor —OR² forms a substituted cyclohexane-ester; and

neither —OR¹ nor —OR² forms an ester with or of an amino acid (protectedor unprotected), a peptide or a protein.

In other embodiments, treprostinil derivatives have the structure ofFormula (II):

wherein —O—Z—CO₂H

—O-heteroalkyl-CO₂H, —O-cyclyl-CO₂H, —O—CH₂-cyclyl-CO₂H,—O-cyclyl-CH₂—CO₂H, or —O—CH₂-cyclyl-CH₂—CO₂H, each of which mayoptionally be substituted, and -cyclyl-, -heteroalkyl-, R⁷, R⁸ and n areas described herein, with the proviso that:

—O—Z—CO₂H is not

and

—O—Z—CO₂H does not contain a sugar moiety.

The treprostinil derivatives can be used to treat any conditionsresponsive to treatment with treprostinil, including pulmonaryhypertension (e.g., PAH). In some embodiments, the treprostinilderivatives are administered topically, such as transdermally (e.g., viaa transdermal patch).

DETAILED DESCRIPTION OF THE DISCLOSURE

While various embodiments of the present disclosure are describedherein, it will be obvious to those skilled in the art that suchembodiments are provided by way of example only. Numerous modificationsand changes to, and variations and substitutions of, the embodimentsdescribed herein will be apparent to those skilled in the art withoutdeparting from the disclosure. It is understood that variousalternatives to the embodiments described herein may be employed inpracticing the disclosure. It is also understood that every embodimentof the disclosure may optionally be combined with any one or more of theother embodiments described herein which are consistent with thatembodiment.

Where elements are presented in list format (e.g., in a Markush group),it is understood that each possible subgroup of the elements is alsodisclosed, and any one or more elements can be removed from the list orgroup.

It is also understood that, unless clearly indicated to the contrary, inany method described or claimed herein that includes more than one actor step, the order of the acts or steps of the method is not necessarilylimited to the order in which the acts or steps of the method arerecited, but the disclosure encompasses embodiments in which the orderis so limited.

It is further understood that, in general, where an embodiment in thedescription or the claims is referred to as comprising one or morefeatures, the disclosure also encompasses embodiments that consist of,or consist essentially of, such feature(s).

It is also understood that any embodiment of the disclosure, e.g., anyembodiment found within the prior art, can be explicitly excluded fromthe claims, regardless of whether or not the specific exclusion isrecited in the specification.

Headings are included herein for reference and to aid in locatingcertain sections. Headings are not intended to limit the scope of theembodiments and concepts described in the sections under those headings,and those embodiments and concepts may have applicability in othersections throughout the entire disclosure.

All patent literature and all non-patent literature cited herein areincorporated herein by reference in their entirety to the same extent asif each patent literature or non-patent literature were specifically andindividually indicated to be incorporated herein by reference in itsentirety.

I. Definitions

As used in the specification and the appended claims, the indefinitearticles “a” and “an” and the definite article “the” can include pluralreferents as well as singular referents unless specifically statedotherwise.

The term “about” or “approximately” means an acceptable error for aparticular value as determined by one of ordinary skill in the art,which depends in part on how the value is measured or determined. Incertain embodiments, the term “about” or “approximately” means withinone standard deviation. In some embodiments, when no particular marginof error (e.g., a standard deviation to a mean value given in a chart ortable of data) is recited, the term “about” or “approximately” meansthat range which would encompass the recited value and the range whichwould be included by rounding up or down to the recited value as well,taking into account significant figures. In certain embodiments, theterm “about” or “approximately” means within 10% or 5% of the specifiedvalue. Whenever the term “about” or “approximately” precedes the firstnumerical value in a series of two or more numerical values or in aseries of two or more ranges of numerical values, the term “about” or“approximately” applies to each one of the numerical values in thatseries of numerical values or in that series of ranges of numericalvalues.

Whenever the term “at least” or “greater than” precedes the firstnumerical value in a series of two or more numerical values, the term“at least” or “greater than” applies to each one of the numerical valuesin that series of numerical values.

Whenever the term “no more than” or “less than” precedes the firstnumerical value in a series of two or more numerical values, the term“no more than” or “less than” applies to each one of the numericalvalues in that series of numerical values.

The term “pharmaceutically acceptable” refers to a substance (e.g., anactive ingredient or an excipient) that is suitable for use in contactwith the tissues and organs of a subject without excessive irritation,allergic response, immunogenecity and toxicity, is commensurate with areasonable benefit/risk ratio, and is effective for its intended use. A“pharmaceutically acceptable” excipient or carrier of a pharmaceuticalcomposition is also compatible with the other ingredients of thecomposition.

The term “therapeutically effective amount” refers to an amount of acompound that, when administered to a subject, is sufficient to preventdevelopment of, or to alleviate to some extent, the medical conditionbeing treated or one or more symptoms associated with the condition. Theterm “therapeutically effective amount” also refers to an amount of acompound that is sufficient to elicit the biological or medical responseof a cell, tissue, organ, system, animal or human which is sought by aresearcher, veterinarian, medical doctor or clinician.

The terms “treat”, “treating”, and “treatment” include alleviating orabrogating a medical condition or one or more symptoms associated withthe condition, and alleviating or eradicating one or more causes of thecondition. Reference to “treatment” of a condition is intended toinclude prevention of the condition. The terms “prevent”, “preventing”,and “prevention” include precluding or delaying the onset of a medicalcondition or one or more symptoms associated with the condition,precluding a subject from acquiring a condition, and reducing asubject's risk of acquiring a condition. The term “medical conditions”includes diseases and disorders.

The term “subject” refers to an animal, including but not limited to amammal, such as a primate (e.g., a human, a chimpanzee and a monkey), arodent (e.g., a rat, a mouse, a gerbil and a hamster), a lagomorph(e.g., a rabbit), a swine (e.g., a pig), an equine (e.g., a horse), acanine (e.g., a dog) and a feline (e.g., a cat). The terms “subject” and“patient” are used interchangeably herein in reference to, e.g., amammalian subject, such as a human subject.

The term “compound” encompasses salts, solvates, hydrates, clathratesand polymorphs of that compound. A “solvate” of a compound includes astoichiometric or non-stoichiometric amount of a solvent (e.g., water,acetone or an alcohol [e.g., ethanol]), bound non-covalently to thecompound. A “hydrate” of a compound includes a stoichiometric ornon-stoichiometric amount of water bound non-covalently to the compound.A “clathrate” of a compound contains molecules of a substance (e.g., asolvent) enclosed in the crystal structure of the compound. A“polymorph” of a compound is a crystalline form of the compound. Thespecific recitation of “salt”, “solvate”, “hydrate”, “clathrate” or“polymorph” with respect to a compound in certain instances of thedisclosure shall not be interpreted as an intended omission of any ofthese forms in other instances of the disclosure where the term“compound” is used without recitation of any of these forms.

The terms “halogen”, “halide” and “halo” refer to fluoride, chloride,bromide and iodide.

The term “alkyl” refers to a linear or branched, saturated monovalenthydrocarbon radical, wherein the alkyl group may optionally besubstituted with one or more substituents as described herein. Incertain embodiments, an alkyl group is a linear saturated monovalenthydrocarbon radical that has 1 to 20 (C₁₋₂₀), 1 to 10 (C₁₋₁₀), or 1 to 6(C₁₋₆) carbon atoms, or is a branched saturated monovalent hydrocarbonradical that has 3 to 20 (C₃₋₂₀), 3 to 10 (C₃₋₁₀), or 3 to 6 (C₃₋₆)carbon atoms. As an example, the term “C₁₋₆ alkyl” refers to a linearsaturated monovalent hydrocarbon radical of 1 to 6 carbon atoms or abranched saturated monovalent hydrocarbon radical of 3 to 6 carbonatoms. Linear C₁₋₆ and branched C₃₋₆ alkyl groups may also be referredto as “lower alkyl”. Non-limiting examples of alkyl groups includemethyl, ethyl, propyl (including all isomeric forms, such as n-propyland isopropyl), butyl (including all isomeric forms, such as n-butyl,isobutyl, sec-butyl and tert-butyl), pentyl (including all isomericforms, such as n-pentyl), and hexyl (including all isomeric forms, suchas n-hexyl).

The terms “alkylene” and “-alkyl-” refer to a divalent alkyl group,which may optionally be substituted with one or more substituents asdescribed herein.

The term “heteroalkyl” refers to a linear or branched, saturatedmonovalent hydrocarbon group containing one or more heteroatomsindependently selected from O, N and S. The terms “heteroalkylene” and“-heteroalkyl-” refer to a divalent heteroalkyl group. A heteroalkylgroup and a -heteroalkyl- group may optionally be substituted with oneor more substituents as described herein. Examples of heteroalkyl and-heteroalkyl- groups include without limitation —(CH₂)₂—(O or S)—CH₂CH₃and —(CH₂)₂—(O or S)—(CH₂)₂—.

The term “alkoxy” refers to an —O-alkyl group, which may optionally besubstituted with one or more substituents as described herein.

The term “-alkylaryl” refers to an alkyl group that is substituted withone or more aryl groups. An -alkylaryl group may optionally besubstituted with one or more additional substituents as describedherein.

The term “cycloalkyl” refers to a cyclic saturated, bridged ornon-bridged monovalent hydrocarbon radical, which may optionally besubstituted with one or more substituents as described herein. Incertain embodiments, a cycloalkyl group has from 3 to 10 (C₃₋₁₀), orfrom 3 to 8 (C₃₋₈), or from 3 to 6 (C₃₋₆) carbon atoms. Non-limitingexamples of cycloalkyl groups include cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, norbornyl, decalinyland adamantyl. The term “-cycloalkyl-” refers to a divalent cycloalkylgroup, which may optionally be substituted with one or more substituentsas described herein.

The terms “heterocyclyl” and “heterocyclic” refer to a monocyclicnon-aromatic group or a multicyclic group that contains at least onenon-aromatic ring, wherein at least one non-aromatic ring contains oneor more heteroatoms independently selected from O, N and S. Thenon-aromatic ring containing one or more heteroatoms may be attached orfused to one or more saturated, partially unsaturated or aromatic rings.In certain embodiments, a heterocyclyl or heterocyclic group has from 3to 15, or 3 to 12, or 3 to 10, or 3 to 8, or 3 to 6 ring atoms. In someembodiments, a heterocyclyl or heterocyclic group is a monocyclic,bicyclic or tricyclic ring system, which may include a fused or bridgedring system, and in which nitrogen or sulfur atoms may optionally beoxidized, nitrogen atoms may optionally be quaternized, and one or morerings may be fully or partially saturated, or aromatic. A heterocyclylor heterocyclic group may be attached to the main structure at anyheteroatom or carbon atom which results in the creation of a stablecompound. Examples of heterocyclyl or heterocyclic groups includewithout limitation azepinyl, azetidinyl, aziridinyl, benzodioxanyl,benzodioxolyl, benzofuranonyl, benzopyranonyl, benzopyranyl,benzotetrahydrofuranyl, benzotetrahydrothienyl, benzothiopyranyl,β-carbolinyl, chromanyl, decahydroisoquinolinyl,dihydrobenzisothiazinyl, dihydrobenzisoxazinyl, dihydrofuryl,dihydropyranyl, dihydropyrazinyl, dihydropyridinyl, dihydropyrazolyl,dihydropyrimidinyl, dihydropyrrolyl, dioxolanyl, dithianyl, furanonyl,imidazolidinyl, imidazolinyl, indolinyl, indolizinyl,isobenzotetrahydrofuranyl, isobenzotetrahydrothienyl, isochromanyl,isoindolinyl, isothiazolidinyl, isoxazolidinyl, morpholinyl,octahydroindolyl, octahydroisoindolyl, oxazolidinonyl, oxazolidinyl,oxiranyl, piperazinyl, piperidinyl, 4-piperidonyl, pyrrolidinyl,pyrrolinyl, quinuclidinyl, tetrahydrofuryl, tetrahydrofuranyl(oxolanyl), tetrahydroisoquinolinyl, tetrahydropyranyl,tetrahydrothienyl (tetrahydrothiophenyl, thiolanyl), thiamorpholinyl(thiomorpholinyl), thiazolidinyl and 1,3,5-trithianyl. The term“-heterocyclyl” refers to a divalent heterocyclyl group. A heterocyclylor heterocyclic group, and a -heterocyclyl- group, may optionally besubstituted with one or more substituents as described herein.

The term “aryl” refers to a monocyclic aromatic hydrocarbon group or amulticyclic group that contains at least one aromatic hydrocarbon ring.In certain embodiments, an aryl group has from 6 to 15, or 6 to 12, or 6to 10 ring atoms. Non-limiting examples of aryl groups include phenyl,naphthyl, fluorenyl, azulenyl, anthryl, phenanthryl, biphenyl andterphenyl. The aromatic hydrocarbon ring of an aryl group may beattached or fused to one or more saturated, partially unsaturated oraromatic rings—e.g., dihydronaphthyl, indenyl, indanyl andtetrahydronaphthyl (tetralinyl). The term “-aryl-” refers to a divalentaryl group. An aryl group and an -aryl- group may optionally besubstituted with one or more substituents as described herein.

The term “heteroaryl” refers to a monocyclic aromatic group or amulticyclic group that contains at least one aromatic ring, wherein atleast one aromatic ring contains one or more heteroatoms independentlyselected from O, N and S. The heteroaromatic ring may be attached orfused to one or more saturated, partially unsaturated or aromatic ringsthat may contain only carbon atoms or that may contain one or moreheteroatoms. A heteroaryl group may be attached to the main structure atany heteroatom or carbon atom which results in the creation of a stablecompound. In certain embodiments, a heteroaryl group has from 5 to 15,or 5 to 12, or 5 to 10 ring atoms. Examples of monocyclic heteroarylgroups include without limitation pyrrolyl, pyrazolyl, pyrazolinyl,imidazolyl, oxazolyl, isoxazolyl, thiazolyl, thiadiazolyl, isothiazolyl,furanyl, thienyl (thiophenyl), oxadiazolyl, triazolyl, tetrazolyl,pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl and triazinyl. Non-limitingexamples of bicyclic heteroaryl groups include indolyl, benzothiazolyl,benzothiadiazolyl, benzoxazolyl, benzisoxazolyl, benzothienyl(benzothiophenyl), quinolinyl, tetrahydroisoquinolinyl, isoquinolinyl,benzimidazolyl, benzotriazolyl, indolizinyl, benzofuranyl,isobenzofuranyl, chromonyl, coumarinyl, cinnolinyl, quinazolinyl,quinoxalinyl, indazolyl, naphthyridinyl, phthalazinyl, quinazolinyl,purinyl, pyrrolopyridinyl, furopyridinyl, thienopyridinyl,dihydroisoindolyl and tetrahydroquinolinyl. Examples of tricyclicheteroaryl groups include without limitation carbazolyl, benzindolyl,dibenzofuranyl, phenanthrollinyl, acridinyl, phenanthridinyl andxanthenyl. The term “-heteroaryl-” refers to a divalent heteroarylgroup. A heteroaryl group and a -heteroaryl- group may optionally besubstituted with one or more substituents as described herein.

Each group described herein (including without limitation alkyl,heteroalkyl, alkylaryl, cycloalkyl, heterocyclyl, aryl and heteroaryl),whether as a primary group or as a substituent group, may optionally besubstituted with one or more substituents. In certain embodiments, eachgroup described herein may optionally be substituted with one to sixsubstituents independently selected from the group consisting of halide,cyano, nitro, hydroxyl, sulfhydryl (—SH), amino (—NH₂), —OR¹¹, —SR¹¹,—NR¹²R¹³, —C(═O)R¹¹, —C(═O)OR¹¹, —OC(═O)R¹¹, —C(═O)NR¹²R¹³,—NR¹¹C(═O)R¹¹, alkyl, cycloalkyl, heterocyclyl, aryl and heteroaryl,wherein:

-   -   R¹¹ in each occurrence independently is hydrogen, alkyl,        cycloalkyl, heterocyclyl, aryl or heteroaryl; and    -   R¹² and R¹³ in each occurrence independently are hydrogen,        alkyl, cycloalkyl, heterocyclyl, aryl or heteroaryl, or R¹² and        R¹³ and the nitrogen atom to which they are connected form a        heterocyclic or heteroaryl ring.

II. Stereoisomers

It is understood that the present disclosure encompasses all possiblestereoisomers, including all possible diastereomers and enantiomers andracemic mixtures of enantiomers, of the compounds described herein, andnot only the specific stereoisomers as indicated by drawn structure ornomenclature. Some embodiments of the disclosure relate to the specificstereoisomers indicated by drawn structure or nomenclature. The specificrecitation of the phrase “or stereoisomers thereof” or the like withrespect to a compound in certain instances of the disclosure shall notbe interpreted as an intended omission of any of the other possiblestereoisomers of the compound in other instances of the disclosure wherethe term “compound” is used without recitation of the phrase “orstereoisomers thereof” or the like.

III. Treprostinil Derivatives

The present disclosure provides treprostinil derivatives that canfunction as prodrugs of treprostinil. In some embodiments, atreprostinil derivative is of Formula (I):

wherein:

-   -   R¹ and R² independently are hydrogen,

-   -    wherein:    -   R³ in each occurrence independently is alkyl, -alkylaryl,        cycloalkyl, heterocyclyl, aryl or heteroaryl, each of which may        optionally be substituted;    -   R⁴ and R⁵ in each occurrence independently are hydrogen, C₁-C₆        alkyl or C₃-C₆ cycloalkyl, or R⁴ and R⁵ and the carbon atom to        which they are connected form a C₃-C₆ cycloalkyl ring;    -   R⁶ in each occurrence independently is hydrogen, R³, —C(═O)R³,        —C(═O)OR³ or —C(═O)NR⁹R¹⁰; or    -   R⁶ and R⁴ or R⁵, together with the atoms to which they are        connected, form a heterocyclic ring;    -   R⁹ and R¹⁰ in each occurrence independently are hydrogen, alkyl,        -alkylaryl, cycloalkyl, heterocyclyl, aryl or heteroaryl; or        -   R⁹ and R¹⁰ and the nitrogen atom to which they are connected            form a heterocyclic or heteroaryl ring;

j in each occurrence independently is an integer from 0 to 4; and

m in each occurrence independently is an integer from 1 to 10;

or a pharmaceutically acceptable salt, solvate, hydrate, clathrate,polymorph or stereoisomer thereof, with the proviso that:

both R¹ and R² are not hydrogen;

neither —OR¹ nor —OR² forms an acetate;

neither —OR¹ nor —OR² forms a substituted cyclohexane-ester; and

neither —OR¹ nor —OR² forms an ester with or of an amino acid (protectedor unprotected), a peptide or a protein.

In certain embodiments, R³ in

is not alkyl substituted with a nitrogen-containing group, or notcycloalkyl substituted with a carbonyl-containing group. In furtherembodiments, neither the alkyl nor the cycloalkyl group of R³ in

is substituted. In yet further embodiments, none of the alkyl,-alkylaryl, cycloalkyl, heterocyclyl, aryl or heteroaryl group of R³ in

is substituted.

In some embodiments, j in each occurrence independently is 0, 1 or 2. Incertain embodiments, j is 0. In further embodiments, m in eachoccurrence independently is an integer from 1 to 6.

In some embodiments, R¹ and R² independently are

wherein R⁴, R⁵, R⁶ and m are as defined above, and k in each occurrenceindependently is an integer from 1 to 9. In certain embodiments, k ineach occurrence independently is an integer from 1 to 5.

In further embodiments, R³ in each occurrence independently is C₁-C₆alkyl; R⁴ and R⁵ in each occurrence independently are hydrogen or C₁-C₃alkyl, or R⁴ and R⁵ and the carbon atom to which they are connected forma cyclopropyl ring; R⁶ in each occurrence independently is hydrogen orR³; j in each occurrence independently is 0 or 1; and m in eachoccurrence independently is 1 or 2. In certain embodiments, R³ in eachoccurrence independently is methyl, ethyl, propyl, isopropyl, butyl,iso-butyl, sec-butyl or tert-butyl; R⁴ and R⁵ in each occurrenceindependently are hydrogen, methyl, ethyl, propyl or isopropyl; R⁶ ineach occurrence independently is hydrogen or R³; j is 0; and mist.

In some embodiments, R¹ and R² independently are selected from the groupconsisting of:

hydrogen,

wherein each moiety that has a stereocenter adjacent to the carbonylgroup can have the (R)-stereochemistry or the (S)-stereochemistry or canbe racemic at that stereocenter;

with the proviso that both R¹ and R² are not hydrogen.

The disclosure specifically describes treprostinil derivatives in which:(1) R² is hydrogen and —OR¹ is derivatized with each of the moieties(other than hydrogen) in the preceding group; (2) R¹ is hydrogen and—OR² is derivatized with each of the moieties (other than hydrogen) inthe preceding group; and (3) both —OR¹ and —OR² are derivatized with thesame moiety and with each of the moieties (other than hydrogen) in thepreceding group. In certain embodiments, R¹ and R² independently areselected from the group consisting of:

hydrogen,

with the proviso that both R¹ and R² are not hydrogen.

In some embodiments, both —OR¹ and —OR² are derivatized [Formula (Ic)],optionally with the same group. In other embodiments, R² is hydrogen and—OR¹ is derivatized [Formula (Ia)]. In yet other embodiments, R¹ ishydrogen and —OR² is derivatized [Formula (Ib)].

In certain embodiments, a treprostinil derivative of Formula (I) isselected from the group consisting of:

and pharmaceutically acceptable salts, solvates, hydrates, clathrates,polymorphs and stereoisomers thereof.

In other embodiments, a treprostinil derivative is of Formula (II):

wherein:

—O—Z—CO₂H is

—O-heteroalkyl-CO₂H, —O-cyclyl-CO₂H, —O—CH₂-cyclyl-CO₂H,—O-cyclyl-CH₂—CO₂H, or —O—CH₂-cyclyl-CH₂—CO₂H, each of which mayoptionally be substituted,

wherein:

-   -   cyclyl- is -cycloalkyl-, -heterocyclyl-, -aryl- or -heteroaryl-;    -   R⁷ and R⁸ in each occurrence independently are hydrogen, C₁-C₆        alkyl or C₃-C₆ cycloalkyl, or R⁷ and R⁸ and the carbon atom to        which they are connected form a C₃-C₆ cycloalkyl ring; and    -   n is an integer from 1 to 10;        or a pharmaceutically acceptable salt, solvate, hydrate,        clathrate, polymorph or stereoisomer thereof, with the proviso        that:

—O—Z—CO₂H is not

and

—O—Z—CO₂H does not contain a sugar moiety.

In some embodiments, n is an integer from 1 to 6.

In certain embodiments, —O—Z—CO₂H does not contain a -heterocyclyl-group, or a substituted -heterocyclyl- group.

In some embodiments, —O—Z—CO₂H is

wherein R⁷ and R⁸ are as defined above, p is an integer from 1 to 9, andq is an integer from 0 to 8, with the proviso that —O—Z—CO₂H is not

In certain embodiments, p is an integer from 1 to 5, and q is an integerfrom 0 to 4. In some embodiments, both R⁷ and R⁸ are hydrogen, and p isan integer from 1 to 5 or from 1 to 3 (or each occurrence of R⁷ and R⁸is hydrogen, and q is an integer from 0 to 4 or from 0 to 2). Thedisclosure specifically describes treprostinil derivatives in which bothR⁷ and R⁸ are hydrogen, and p is each of 1, 2, 3, 4, 5, 6, 7, 8 and 9.In further embodiments, —O—Z—CO₂H is

and p is 2, 3, 4 or 5. The disclosure specifically describestreprostinil derivatives in which —O—Z—CO₂H is

and p is each of 2, 3, 4, 5, 6, 7, 8 and 9, wherein the stereocenterconnected to the methyl group can have the (R)-stereochemistry or the(S)-stereochemistry or can be racemic at that position.

In other embodiments, —O—Z—CO₂H is —O-heteroalkyl-CO₂H, and—O-heteroalkyl-CO₂H is selected from the group consisting of:

wherein r is each of 1, 2 and 3; and

wherein each moiety that has a stereocenter adjacent to the oxygen atomconnected to treprostinil, and/or a stereocenter adjacent to thecarboxyl group, independently can have the (R)-stereochemistry or the(S)-stereochemistry or can be racemic at that (those) stereocenter(s).The disclosure specifically describes treprostinil derivatives in which—O—Z—CO₂H is each of the moieties in the preceding group. In certainembodiments, —O—Z—CO₂H is

wherein r is 1, 2 or 3.

In further embodiments, —O—Z—CO₂H is —O-cycloalkyl-CO₂H,—O—CH₂-cycloalkyl-CO₂H, —O-cycloalkyl-CH₂—CO₂H, or—O—CH₂-cycloalkyl-CH₂—CO₂H, and for each of the preceding moieties-cycloalkyl- is:

1,2-cyclopropyl (cis or trans); or

1,3-cyclobutyl (cis or trans) or 1,2-cyclobutyl (cis or trans); or

1,3-cyclopentyl (cis or trans) or 1,2-cyclopentyl (cis or trans); or

1,4-cyclohexyl (cis or trans), 1,3-cyclohexyl (cis or trans), or1,2-cyclohexyl (cis or trans). The disclosure specifically describes the64 treprostinil derivatives in which —O—Z—CO₂H is each of the moietiesin the preceding group. In certain embodiments, —O—Z—CO₂H is selectedfrom the group consisting of:

wherein for each of the moieties the two groups on the cycloalkyl ringcan be cis or trans relative to one another.

In some embodiments, a treprostinil derivative of Formula (II) isselected from the group consisting of:

and pharmaceutically acceptable salts, solvates, hydrates, clathrates,polymorphs and stereoisomers thereof.

The treprostinil derivatives described herein can exist or be used inthe form of a pharmaceutically acceptable salt. The treprostinilderivatives have a carboxyl group, and thus can form an addition saltwith a base. Pharmaceutically acceptable base addition salts can beformed with, e.g., metals (e.g., alkali metals or alkaline earth metals)or amines (e.g., organic amines). Examples of metals useful as cationsinclude without limitation alkali metals (e.g., lithium, sodium,potassium and cesium), alkaline earth metals (e.g., magnesium andcalcium), aluminum and zinc. Metal cations can be provided by way of,e.g., inorganic bases, such as hydroxides, carbonates and hydrogencarbonates. Non-limiting examples of organic amines useful for formingbase addition salts include chloroprocaine, choline, cyclohexylamine,dibenzylamine, N,N′-dibenzylethylene-diamine, dicyclohexylamine,diethanolamine, ethylenediamine, N-ethylpiperidine, histidine,isopropylamine, N-methylglucamine, procaine, pyrazine, triethylamine,trimethylamine and tromethamine.

If a compound has a basic atom or functional group (e.g., a basicnitrogen atom), the compound can form an addition salt with an acid.Non-limiting examples of acids useful for forming acid addition saltsinclude mineral acids (e.g., HCl, HBr, HI, nitric acid, phosphoric acidand sulfuric acid) and organic acids, such as carboxylic acids (e.g.,acetic acid) and sulfonic acids (e.g., ethanesulfonic acid).Pharmaceutically acceptable salts are discussed in detail in Handbook ofPharmaceutical Salts, Properties, Selection and Use, P. Stahl and C.Wermuth, Eds., Wiley-VCH (2011).

IV. Deuterated Treprostinil Compounds

To eliminate foreign substances such as drugs, the animal body expressesa variety of enzymes, such as cytochrome P₄₅₀ enzymes, esterases,proteases, reductases, dehydrogenases and monoamine oxidases, whichreact with and convert the foreign substances to more polarintermediates or metabolites for renal excretion. Such metabolicreactions can involve the oxidation of a carbon-hydrogen (C—H) bond to acarbon-oxygen (C—O) bond or a carbon-carbon (C═C) pi bond. The resultingmetabolites may be stable or unstable under physiological conditions,and may have substantially different pharmacologic, pharmacokinetic andpharmacodynamic properties and toxicity profiles compared to the parentcompounds. For many drugs, such metabolic oxidations can be rapid andlead to the requirement of higher dosage amounts and/or increased dosingfrequencies, which can result in greater side effects.

The present disclosure provides treprostinil isotopologues correspondingto the treprostinil derivatives described herein which are enriched withdeuterium (deuterated) at one or more positions. In some embodiments, atreprostinil derivative is deuterated at one or more positions in theparent treprostinil structure so that when the derivative is convertedto treprostinil in vivo, the resulting active parent drug is deuteratedat one or more positions.

Deuteration of a treprostinil compound at one or more positions can haveany one or more, or all, of the following benefits: (1) a longerhalf-life; (2) decreased amount of a dose and/or decreased number ofdoses needed to achieve a desired effect; (3) decreased variationbetween subjects in the blood or plasma level of the parent drug; (4)increased efficacy; (5) reduced side effects due to decreased amount ofthe parent drug administered and/or decreased production of deleteriousmetabolites; and (6) increased maximum tolerated dose.

Deuterium can be substituted for hydrogen at any one or more, or all, ofthe available positions in a treprostinil (Trp) compound, including atany one or more, or all, of the available positions in the phenyl ringof Trp, the cyclohexyl ring of Trp, the cyclopentyl ring of Trp, theoctyl chain of Trp, or the hydroxyacetic acid group of Trp, or anycombination thereof. In certain embodiments, a treprostinil derivativeis deuterated at one or more, or all, of the available positions in thecyclohexyl ring of Trp and/or the hydroxyacetic acid group of Trp. Insome embodiments, at least one of the available positions has deuteriumenrichment of at least about 10%, 25%, 50%, 75%, 90%, 95% or 98%. Incertain embodiments, at least one of the available positions hasdeuterium enrichment of at least about 90%, 95% or 98%.

In further embodiments, each position in a treprostinil derivativeenriched with deuterium (or deuterated) independently has deuteriumenrichment of at least about 10%, 25%, 50%, 75%, 90%, 95% or 98%. Incertain embodiments, each position enriched with deuterium independentlyhas deuterium enrichment of at least about 90%, 95% or 98%.

Deuterated treprostinil derivatives can also contain less prevalentisotopes for other elements, including without limitation ¹³C or ¹⁴C forcarbon and ¹⁷O or ¹⁸O for oxygen.

The term “deuterium enrichment” refers to the percentage ofincorporation of deuterium at a given position in a molecule in place ofhydrogen. For example, deuterium enrichment of 10% at a given positionmeans that 10% of molecules in a given sample contain deuterium at thatposition. Because the naturally occurring distribution of deuterium isabout 0.0156%, deuterium enrichment at any position in a moleculesynthesized using non-deuterium-enriched starting materials or reagentsis about 0.0156%. Deuterium enrichment can be determined usingconventional analytical methods known to one of ordinary skill in theart, including mass spectrometry and nuclear magnetic resonancespectroscopy.

The term “is deuterium” or “is deuterated”, when used to describe agiven position in a molecule, or the symbol “D”, when used to representan element at a given position in a drawing of a molecular structure,means that the specified position is enriched with deuterium above thenaturally occurring distribution of deuterium. In some embodiments,deuterium enrichment is at least about 10%, 20%, 30%, 40%, 50%, 60%,70%, 80%, 90%, 95%, 98% or 99% (e.g., at least about 50%) of deuteriumat the specified position. In certain embodiments, deuterium enrichmentis at least about 90%, 95% or 98% of deuterium at the specifiedposition.

V. Pharmaceutical Compositions

Additional embodiments of the disclosure relate to pharmaceuticalcompositions comprising one or more treprostinil derivatives describedherein, or a pharmaceutically acceptable salt, solvate, hydrate,clathrate or polymorph thereof, and one or more pharmaceuticallyacceptable excipients or carriers. The compositions can optionallycontain an additional therapeutic agent.

Pharmaceutically acceptable excipients and carriers includepharmaceutically acceptable substances, materials and vehicles.Non-limiting examples of excipients include liquid and solid fillers,diluents, binders, lubricants, glidants, surfactants, dispersing agents,disintegration agents, emulsifying agents, wetting agents, suspendingagents, thickeners, solvents, isotonic agents, buffers, pH adjusters,absorption-delaying agents, sweetening agents, flavoring agents,coloring agents, stabilizers, preservatives, antioxidants, antimicrobialagents, antibacterial agents, antifungal agents, adjuvants,encapsulating materials and coating materials. The use of suchexcipients in pharmaceutical formulations is known in the art. Forexample, conventional vehicles and carriers include without limitationoils (e.g., vegetable oils, such as sesame oil), aqueous solvents (e.g.,saline and phosphate-buffered saline [PBS]), and solvents (e.g.,dimethyl sulfoxide [DMSO] and alcohols [such as ethanol and glycerol]).Except insofar as any conventional excipient or carrier is incompatiblewith the active ingredient (for purposes of the content of apharmaceutical composition, the term “active ingredient” encompasses aprodrug), the disclosure encompasses the use of conventional excipientsand carriers in formulations containing treprostinil derivatives. See,e.g., Remington: The Science and Practice of Pharmacy, 21st Ed.,Lippincott Williams & Wilkins (Philadelphia, Pa. [2005]); Handbook ofPharmaceutical Excipients, 5th Ed., Rowe et al., Eds., ThePharmaceutical Press and the American Pharmaceutical Association (2005);Handbook of Pharmaceutical Additives, 3rd Ed., Ash and Ash, Eds., GowerPublishing Co. (2007); and Pharmaceutical Pre-formulation andFormulation, Gibson, Ed., CRC Press LLC (Boca Raton, Fla. [2004]).

Proper formulation can depend on various factors, such as the route ofadministration chosen. Potential routes of administration ofpharmaceutical compositions comprising treprostinil derivatives includewithout limitation oral, parenteral (including intradermal,subcutaneous, intramuscular, intravascular, intravenous, intraarterial,intramedullary and intrathecal), intracavitary, intraperitoneal, andtopical (including dermal/epicutaneous, transdermal, mucosal,transmucosal, intranasal [e.g., by nasal spray or drop], intraocular[e.g., by eye drop], pulmonary [e.g., by inhalation], buccal,sublingual, rectal and vaginal). Topical formulations can be designed toproduce a local or systemic therapeutic effect.

As an example, formulations of treprostinil derivatives suitable fororal administration can be presented as, e.g., capsules (includingpush-fit capsules and soft capsules), cachets or tablets; as powders orgranules; or as boluses, electuaries or pastes. For example, push-fitcapsules can contain a treprostinil derivative in admixture with, e.g.,a filler (e.g., lactose), a binder (e.g., a starch) and a lubricant(e.g., talc or magnesium stearate), and optionally a stabilizer. Forsoft capsules, a treprostinil derivative can be dissolved or suspendedin a suitable liquid (e.g., a fatty oil, liquid paraffin or liquidpolyethylene glycol), and a stabilizer can be added.

Compositions for oral administration can also be formulated as solutionsor suspensions in an aqueous liquid and/or a non-aqueous liquid, or asoil-in-water liquid emulsions or water-in-oil liquid emulsions.Dispersible powder or granules of a treprostinil derivative can be mixedwith any suitable combination of an aqueous liquid, an organic solventand/or an oil and any suitable excipients (e.g., any combination of adispersing agent, a wetting agent, a suspending agent, an emulsifyingagent and/or a preservative) to form a solution, suspension or emulsion.

Treprostinil derivatives can also be formulated for parenteraladministration by injection or infusion to circumvent gastrointestinalabsorption and first-pass metabolism. An exemplary parenteral route isintravenous. Additional advantages of intravenous administration includedirect administration of a therapeutic agent into systemic circulationto achieve a rapid systemic effect, and the ability to administer theagent continuously and/or in a large volume if desired. Formulations forinjection or infusion can be in the form of, e.g., solutions,suspensions or emulsions in oily or aqueous vehicles, and can containexcipients such as suspending agents, dispersing agents and/orstabilizing agents. For example, aqueous or non-aqueous (e.g., oily)sterile injection solutions can contain a treprostinil derivative alongwith excipients such as an antioxidant, a buffer, a bacteriostat andsolutes that render the formulation isotonic with the blood of thesubject. Aqueous or non-aqueous sterile suspensions can contain atreprostinil derivative along with excipients such as a suspending agentand a thickening agent, and optionally a stabilizer and an agent thatincreases the solubility of the treprostinil derivative to allow for thepreparation of a more concentrated solution or suspension. As anotherexample, a sterile aqueous solution for injection or infusion (e.g.,subcutaneously or intravenously) can contain a treprostinil derivative,sodium chloride, a buffering agent (e.g., sodium citrate), apreservative (e.g., meta-cresol), and optionally a base (e.g., NaOH)and/or an acid (e.g., HCl) to adjust pH.

In some embodiments, a topical dosage form of a treprostinil derivativeis formulated as a buccal or sublingual tablet or pill. Advantages of abuccal or sublingual tablet or pill include avoidance ofgastrointestinal absorption and first-pass metabolism, and rapidabsorption into systemic circulation. A buccal or sublingual tablet orpill can be designed to provide faster release of the treprostinilderivative for more rapid uptake of it into systemic circulation. Inaddition to a therapeutically effective amount of a treprostinilderivative, the buccal or sublingual tablet or pill can contain suitableexcipients, including without limitation any combination of fillers anddiluents (e.g., mannitol and sorbitol), binding agents (e.g., sodiumcarbonate), wetting agents (e.g., sodium carbonate), disintegrants(e.g., crospovidone and croscarmellose sodium), lubricants (e.g.,silicon dioxide [including colloidal silicon dioxide] and sodium stearylfumarate), stabilizers (e.g., sodium bicarbonate), flavoring agents(e.g., spearmint flavor), sweetening agents (e.g., sucralose), andcoloring agents (e.g., yellow iron oxide).

In addition, treprostinil derivatives can be formulated for intranasaladministration. Intranasal administration bypasses gastrointestinalabsorption and first-pass metabolism. An intranasal formulation cancomprise a treprostinil derivative along with excipients, such as asolubility enhancer (e.g., propylene glycol), a humectant (e.g.,mannitol or sorbitol), a buffer and water, and optionally a preservative(e.g., benzalkonium chloride), a mucoadhesive agent (e.g.,hydroxyethylcellulose) and/or a penetration enhancer.

Furthermore, treprostinil derivatives can be formulated foradministration by oral inhalation. Advantages of administration byinhalation include avoidance of first-pass metabolism, and the abilityto tailor to rapid delivery of the therapeutic agent across the mucousmembrane of the respiratory tract, or more selective deposition of theagent in the lungs with less systemic side effects. In certainembodiments, a sterile aqueous solution for oral inhalation contains atreprostinil derivative, sodium chloride, a buffering agent (e.g.,sodium citrate), optionally a preservative (e.g., meta-cresol), andoptionally a base (e.g., NaOH) and/or an acid (e.g., HCl) to adjust pH.

For a delayed or sustained release of a treprostinil derivative, acomposition can be formulated as, e.g., a depot that can be implanted inor injected into a subject, e.g., intramuscularly or subcutaneously. Adepot formulation can be designed to deliver the treprostinil derivativeover an extended period of time, e.g., over at least about 1 week, 2weeks, 3 weeks, 1 month, 1.5 months, 2 months or longer. For example, atreprostinil derivative can be formulated with a polymeric material(e.g., polyethylene glycol [PEG], polylactic acid [PLA] or polyglycolicacid [PGA], or a copolymer thereof [e.g., PLGA]), a hydrophobic material(e.g., as an emulsion in an oil) and/or an ion-exchange resin, or as asparingly soluble derivative (e.g., a sparingly soluble salt).

A treprostinil derivative can also be contained or dispersed in a matrixmaterial. The matrix material can comprise a polymer (e.g.,ethylene-vinyl acetate) and controls the release of the compound bycontrolling dissolution and/or diffusion of the compound from, e.g., areservoir, and can enhance the stability of the compound while containedin the reservoir. Such a “release system” can be configured as atransdermal or transmucosal patch and can contain an excipient that canaccelerate the compound's release, such as a water-swellable material(e.g., a hydrogel) that aids in expelling the compound out of thereservoir. U.S. Pat. Nos. 4,144,317 and 5,797,898 describe examples ofsuch a release system.

The release system can provide a temporally modulated release profile(e.g., pulsatile release) when time variation in plasma levels isdesired, or a more continuous or consistent release profile when aconstant plasma level is desired. Pulsatile release can be achieved froman individual reservoir or from a plurality of reservoirs. For example,where each reservoir provides a single pulse, multiple pulses(“pulsatile” release) are achieved by temporally staggering the singlepulse release from each of multiple reservoirs. Alternatively, multiplepulses can be achieved from a single reservoir by incorporating severallayers of a release system and other materials into a single reservoir.Continuous release can be achieved by incorporating a release systemthat degrades, dissolves, or allows diffusion of a compound through itover an extended time period. In addition, continuous release can beapproximated by releasing several pulses of a compound in rapidsuccession (“digital” release). An active release system can be usedalone or in conjunction with a passive release system, as described inU.S. Pat. No. 5,797,898.

The pharmaceutical compositions can be manufactured in any suitablemanner known in the art, e.g., by means of conventional mixing,dissolving, suspending, granulating, dragee-making, levigating,emulsifying, encapsulating, entrapping or compressing processes.

The compositions can be presented in unit dosage form as a single dosewherein all active and inactive ingredients are combined in a suitablesystem, and components do not need to be mixed to form the compositionto be administered. The unit dosage form can contain an effective dose,or an appropriate fraction thereof, of a treprostinil derivative. Arepresentative example of a unit dosage form is a tablet, capsule, orpill for oral uptake.

Alternatively, the compositions can be presented as a kit, wherein theactive ingredient, excipients and carriers (e.g., solvents) are providedin two or more separate containers (e.g., ampules, vials, tubes, bottlesor syringes) and need to be combined to form the composition to beadministered. The kit can contain instructions for storing, preparingand administering the composition (e.g., a solution to be injectedintravenously).

In some embodiments, a kit contains a treprostinil derivative or apharmaceutically acceptable salt, solvate, hydrate, clathrate orpolymorph thereof, and instructions for administering the compound totreat a condition responsive to treatment with treprostinil (e.g.,pulmonary hypertension, such as pulmonary arterial hypertension). Incertain embodiments, the compound is contained or incorporated in, orprovided by, a device or system configured for transdermal delivery ofthe compound (e.g., a transdermal patch).

VI. Topical Compositions, Including Transdermal Delivery Systems

Topical formulations for application to the skin or mucosa can be usefulfor transdermal or transmucosal administration of a therapeutic agentinto the blood for systemic distribution. Advantages of topicaladministration can include circumvention of gastrointestinal absorptionand first-pass metabolism, delivery of a therapeutic agent with a shorthalf-life and low oral bioavailability, more controlled and sustainedrelease of the therapeutic agent, a more uniform plasma dosing ordelivery profile of the therapeutic agent, less frequent dosing of thetherapeutic agent, minimal or no invasiveness, ease ofself-administration, and increased patient compliance. For purposes ofthe content of a pharmaceutical composition, the term “therapeuticagent” or “drug” encompasses a prodrug.

In general and in addition to the disclosure on topical formulationsdescribed elsewhere herein, compositions suitable for topicaladministration include without limitation liquid or semi-liquidpreparations such as sprays, gels, liniments, lotions, oil-in-water orwater-in-oil emulsions such as creams, foams, ointments and pastes, andsolutions or suspensions such as drops (e.g., eye drops, nose drops andear drops). In some embodiments, a topical composition comprises atherapeutic agent dissolved, dispersed or suspended in a carrier. Thecarrier can be in the form of, e.g., a solution, a suspension, anemulsion, an ointment or a gel base, and can contain, e.g., petrolatum,lanolin, a wax (e.g., bee wax), mineral oil, a long-chain alcohol,polyethylene glycol or polypropylene glycol, a diluent (e.g., waterand/or an alcohol [e.g., ethanol or propylene glycol]), an emulsifier, astabilizer or a thickening agent, or any combination thereof. A topicalcomposition can include, or a topical formulation can be administered bymeans of, e.g., a transdermal or transmucosal delivery device, such as atransdermal patch, a microneedle patch or an iontophoresis device. Atopical composition can deliver a drug transdermally or transmucosallyvia a concentration gradient (with or without the use of a chemicalpermeation enhancer) or an active mechanism (e.g., iontophoresis ormicroneedles).

In some embodiments, the treprostinil derivatives described herein areadministered transdermally. In certain embodiments, the topicalcomposition (e.g., transdermal delivery system) comprises a chemicalpermeation enhancer (e.g., a surfactant [e.g., sodium laureth sulfate],optionally in combination with an aromatic compound [e.g.,phenylpiperazine]) that facilitates the transport of a treprostinilderivative across the skin into systemic circulation. In furtherembodiments, the treprostinil derivatives are administered via atransdermal patch. In certain embodiments, a transdermal patch comprisesan impermeable backing membrane or layer, a drug reservoir, asemi-permeable membrane that can serve as a rate-limiting orrate-controlling diffusion barrier, and a skin-contacting adhesivelayer. The semi-permeable membrane can be composed of, e.g., a suitablepolymeric material (e.g., cellulose nitrate or acetate, polyisobutene,polypropylene, polyvinyl acetate or a polycarbonate). Transdermaldrug-delivery systems, including patches, can be designed to providecontrolled and prolonged release of a drug up to, e.g., about 1 week. WO1993/003696 and U.S. Pat. Nos. 3,598,122; 4,144,317; 4,201,211;4,262,003 and 4,379,454 describe various transdermal drug-deliverysystems, including patches, which can deliver a controlled amount of adrug for an extended period of time ranging from several hours toseveral days. Such systems may be adapted for transdermal delivery oftreprostinil derivatives.

VII. Therapeutic Uses of Treprostinil Derivatives

The treprostinil derivatives described herein can be converted totreprostinil in vivo, and thus can act as prodrugs of treprostinil. Insome embodiments, treprostinil derivatives are converted to treprostinilslowly and to an insubstantial extent (e.g., less than about 30%, 20%,10% or 5% conversion) in the blood or the skin (if administered, e.g.,transdermally), and are converted to treprostinil rapidly andsubstantially completely (e.g., at least about 70%, 80%, 90% or 95%conversion) in the liver. In other embodiments, treprostinil derivativesare converted to treprostinil to a substantial extent (e.g., at leastabout 30%, 40%, 50% or 60% conversion), or substantially completely(e.g., at least about 70%, 80%, 90% or 95% conversion), in the blood. Inyet other embodiments, treprostinil derivatives are administeredtransdermally, are converted to treprostinil to some extent (e.g., lessthan about 30%, 20% or 10% conversion) in the skin, and do not cause asignificant amount of side effects in the area of administration, suchas irritation. In further embodiments, the treprostinil derivatives areat least about 50-fold, 100-fold, 500-fold or 1000-fold (e.g., at leastabout 100-fold) less effective in agonizing the prostacyclin receptorthan treprostinil.

Treprostinil, a prostacyclin (prostaglandin 12) analog, has a variety ofprostacyclin-like effects. For example, treprostinil can promotevasodilation, inhibit platelet activation and aggregation, inhibitthrombus formation, stimulate thrombolysis, inhibit atherogenesis,inhibit cell proliferation, inhibit angiogenesis, promote endothelialcell membrane remodeling, reduce inflammation, and providecytoprotection. As prodrugs of treprostinil, the treprostinilderivatives described herein can be used to treat a wide variety ofconditions, including without limitation: pulmonary hypertension,ischemic diseases (e.g., myocardial ischemia, ischemic stroke,peripheral vascular disease, ischemia of a limb, Raynaud's phenomenonand scleroderma), heart failure (e.g., congestive heart failure),conditions requiring anticoagulation (e.g., post myocardial infarctionand post cardiac surgery), atherosclerosis, thrombotic microangiopathy,central retinal vein occlusion, hypertension (e.g., preeclampsia),extracorporeal circulation, inflammatory diseases (e.g., chronicobstructive pulmonary disease [COPD] and psoriasis), renalinsufficiency, reproduction and parturition, conditions of unregulatedcell growth (e.g., cancers and tumors), celUtissue preservation, andother therapeutic areas where prostacyclin or treprostinil treatment mayprovide benefit.

In some embodiments, one or more treprostinil derivatives, orpharmaceutically acceptable salts, solvates, hydrates, clathrates orpolymorphs thereof, are used to treat a prostacyclin- ortreprostinil-responsive condition selected from the group consisting ofpulmonary hypertension, pulmonary fibrosis, peripheral ischemic lesionson the skin (e.g., those caused by scleroderma, Buerger's disease,Raynaud's disease, Raynaud's phenomenon and systemic sclerosis),critical limb ischemia, diabetic neuropathic foot ulcer, kidneymalfunction and failure, peripheral vascular disease, atherogenesis(e.g., atherosclerosis), congestive heart failure, tumors, cancers, andpain associated with each of the preceding conditions.

A treprostinil derivative can be used in conjunction with an additionaltherapeutic agent to treat any condition responsive to treatment withprostacyclin or treprostinil. As a non-limiting example, to treat avascular (e.g., cardiovascular) disorder a treprostinil derivative canbe used in combination with a vascular (e.g., cardiovascular)therapeutic, such as an antiplatelet agent, a phosphodiesteraseinhibitor, a calcium channel blocker or an endothelial antagonist, orany combination thereof.

In some embodiments, the treprostinil derivatives described herein areused to treat pulmonary hypertension. An additional therapeutic agent(e.g., a vasoactive agent, a diuretic and/or an anticoagulant) canoptionally be administered to treat pulmonary hypertension. In certainembodiments, the pulmonary hypertension is pulmonary arterialhypertension.

Pulmonary hypertension is an increase of blood pressure in the lungvasculature, including the pulmonary artery, pulmonary vein andpulmonary capillaries. Thus, pulmonary hypertension encompassespulmonary arterial hypertension (PAH) and pulmonary venous hypertension(PVH) (e.g., congestive heart failure). More broadly, pulmonaryhypertension encompasses:

WHO Group I—pulmonary arterial hypertension, including idiopathic PAH,heritable PAH (e.g., BMPR2, ALK1 and endoglin [with or withouthereditary hemorrhagic telangiectasia]), drug- and toxin-induced PAH,PAH associated with various conditions (e.g., connective tissue disease,HIV infection, portal hypertension, congenital heart disease,schistosomiasis, and chronic hemolytic anemia [e.g., sickle celldisease]), persistent pulmonary hypertension of the newborn, pulmonaryveno-occlusive disease (PVOD), and pulmonary capillary hemangiomatosis(PCH);

WHO Group II—pulmonary hypertension owing to left heart disease,including systolic dysfunction, diastolic dysfunction and valvular heartdisease;

WHO Group III—pulmonary hypertension owing to lung disease and/orhypoxia, including chronic obstructive pulmonary disease (COPD),interstitial lung disease, other pulmonary diseases with mixedrestrictive and obstructive pattern, sleep-disordered breathing,alveolar hypoventilation disorders, chronic exposure to high altitude,and developmental abnormalities;

WHO Group IV—chronic thromboembolic pulmonary hypertension (CTEPH); and

WHO Group V—pulmonary hypertension with unclear multifactorialmechanisms, including hematologic diseases (e.g., myeloproliferativedisease and splenectomy), systemic diseases (e.g., sarcoidosis,pulmonary Langerhans cell histiocytosis, lymphangioleiomyomatosis,neurofibromatosis and vasculitis), metabolic disorders (e.g., glycogenstorage disease, Gaucher disease and thyroid diseases), and other causes(e.g., tumoral obstruction, fibrosing mediastinitis and chronic renalfailure on dialysis).

The therapeutically effective amount and frequency of administration ofa treprostinil derivative to treat, e.g., pulmonary hypertension maydepend on various factors, including the type of pulmonary hypertension,the severity of the condition, the mode of administration, the age, bodyweight, general health, gender and diet of the subject, and the responseof the subject to the treatment, and can be determined by the treatingphysician. In certain embodiments, the effective dose of a treprostinilderivative per day is about 0.1-100 mg, 0.1-50 mg, 0.5-50 mg, 0.5-25 mg,0.5-10 mg, 1-10 mg or 1-5 mg, or as deemed appropriate by the treatingphysician, which can be administered in a single dose or in divideddoses. In further embodiments, the effective dose of a treprostinilderivative per day is about 0.001-2 mg/kg, 0.005-1 mg/kg, 0.01-0.5 mg/kgor 0.01-0.1 mg/kg body weight, or as deemed appropriate by the treatingphysician.

In some embodiments, a treprostinil derivative is administered, in asingle dose or in multiple doses, daily (including one, two, three ormore times daily), every two days, every three days, weekly, every 2weeks, every 3 weeks, monthly, every 6 weeks, every 2 months or every 3months, or as deemed appropriate by the treating physician. In furtherembodiments, a treprostinil derivative is administered under a chronicdosing regimen. In certain embodiments, a therapeutically effectiveamount of a treprostinil derivative is administered over a period of atleast 2 weeks, 3 weeks, 1 month, 1.5 months, 2 months, 3 months, 4months, 5 months, 6 months or longer.

A treprostinil derivative can be administered via any suitable route.Potential routes of administration of a treprostinil derivative includewithout limitation oral, parenteral (including intradermal,subcutaneous, intramuscular, intravascular, intravenous, intraarterial,intramedullary and intrathecal), intracavitary, intraperitoneal, andtopical (including dermal/epicutaneous, transdermal, mucosal,transmucosal, intranasal [e.g., by nasal spray or drop], intraocular[e.g., by eye drop], pulmonary [e.g., by inhalation], buccal,sublingual, rectal and vaginal). In some embodiments, a treprostinilderivative is administered topically (e.g. dermally, transdermally,mucosally, transmucosally, intranasally, pulmonarily [e.g., byinhalation], or sublingually). In certain embodiments, a treprostinilderivative is administered transdermally (e.g., via a transdermalpatch). In other embodiments, a treprostinil derivative is administeredorally. In further embodiments, a treprostinil derivative isadministered parenterally (e.g., subcutaneously or intravenously,including by injection or infusion).

In some embodiments, a treprostinil derivative is used to treat PAH. Incertain embodiments, the treprostinil derivative is administeredtransdermally, e.g., via a transdermal patch. In further embodiments, anadditional therapeutic agent is administered in combination with thetreprostinil derivative to treat PAH. The additional therapeutic agentcan be administered concurrently with or sequentially to (before orafter) administration of the treprostinil derivative. If administeredconcurrently with the treprostinil derivative, the additionaltherapeutic agent can be contained in the same composition as thetreprostinil derivative or in separate compositions.

In certain embodiments, the additional therapeutic agent for thetreatment of PAH is selected from the group consisting of:

vasoactive agents, including without limitation prostaglandins andprostanoids (e.g., prostacyclin [prostaglandin 12] and beraprost),endothelin receptor (e.g., ET_(A) and/or ET_(B)) antagonists (e.g.,ambrisentan, bosentan, sitaxentan and Actelion-1), phosphodiesterasetype 5 (PDE5) inhibitors (e.g., sildenafil and tadalafil), activators ofsoluble guanylate cyclase (e.g., cinaciguat and riociguat), and analogs,derivatives and salts thereof;

diuretics, including without limitation thiazide diuretics (e.g.,bendroflumethiazide, chlorothiazide, epitizide and hydrochlorothiazide),thiazide-like diuretics (e.g., chlorthalidone, indapamide andmetolazone), and analogs, derivatives and salts thereof;

anticoagulants, including without limitation vitamin K antagonists(e.g., acenocoumarol, atromentin, coumarin, phenindione, phenprocoumonand warfarin), direct thrombin inhibitors (e.g., argatroban, dabigatran,hirudin, lepirudin and bivalirudin), direct factor Xa inhibitors (e.g.,apixaban, betrixaban, darexaban, edoxaban, eribaxaban, letaxaban andrivaroxaban), heparin and derivatives thereof (e.g., unfractionatedheparin, low molecular weight heparin, fondaparinux and idraparinux),others (e.g., antithrombin, batroxobin and hementin), and analogs,derivatives, fragments and salts thereof; and

other kinds of therapeutic agents, including without limitation cardiacglycosides (e.g., digoxin, acetyldigoxin and digoxigenin) and oxygentherapy.

VIII. Synthesis of Treprostinil Derivatives

A treprostinil (Trp) derivative of Formula (I) in which R² is hydrogenand —OR¹ is derivatized can be prepared by reacting a Trp compoundappropriately protected at the octyl hydroxyl group and the carboxylgroup (e.g., Compound C in the Examples) with, e.g., a carboxylic acidin the presence of an activating agent (e.g., EDC, DCC, DIC, BOP-Cl, BOPreagent, HATU, HBTU or CDI), or with a pre-prepared activated carbonylcompound (e.g., an acid chloride). The coupling reaction can optionallyinclude an additive (e.g., DMAP, HOSu, HOBT or HOAT) that acceleratesthe reaction, and can also optionally include a non-nucleophilic ornucleophilic base (e.g., TEA, DIPEA, N-methylmorpholine, pyridine orimidazole). The coupling reaction can be run in a suitable solvent orsolvent mixture (e.g., DCM, DMF, THF, dioxane, ethyl acetate oracetonitrile, or any combination thereof). Coupling conditions andreagents, including activating agents, additives and bases, arediscussed in, e.g., Handbook of Reagents for Organic Synthesis:Activating Agents and Protecting Groups, A. Pearson and W. Roush, Eds.,John Wiley and Sons (1999). The bis-protected Trp compound derivatizedat —OR¹ can be deprotected to furnish a Trp derivative of Formula (I)using reagents and conditions known in the art. See, e.g., P. Wuts andT. Greene, Greene's Protective Groups in Organic Synthesis, 4^(th) Ed.,John Wiley and Sons (2006).

A Trp derivative of Formula (I) in which R¹ is hydrogen and —OR² isderivatized can be prepared by appropriately protecting the cyclopentylhydroxyl group of Compound C, deprotecting the octyl hydroxyl groupwithout deprotecting the cyclopentyl hydroxyl group or the carboxylgroup, reacting the octyl hydroxyl group with an activated carbonylcompound (pre-prepared or prepared in situ), and deprotecting thecyclopentyl hydroxyl group and the carboxyl group. A Trp derivative ofFormula (I) in which —OR¹ and —OR² are derivatized with different groupscan be prepared by derivatizing —OR¹ of Compound C as described herein,deprotecting the octyl hydroxyl group, derivatizing —OR², anddeprotecting the carboxyl group. A Trp derivative of Formula (I) inwhich —OR¹ and —OR² are derivatized with the same group can be preparedby deprotecting the octyl hydroxyl group of Compound C, derivatizing—OR¹ and —OR² as described herein, and deprotecting the carboxyl group.

A Trp derivative of Formula (II) can be prepared by reacting a Trpcompound appropriately protected at the octyl hydroxyl group (e.g.,Compound B in the Examples) with an alcohol whose carboxyl group isappropriately protected in the presence of an activating agent asdescribed herein, and deprotecting the octyl hydroxyl group and thecarboxyl group.

The synthesis of representative treprostinil derivatives is described inthe Examples.

IX. Representative Embodiments

The following embodiments of the disclosure are provided by way ofexample only:

1. A compound of Formula (I):

wherein:

R¹ and R² independently are hydrogen,

wherein:

-   -   R³ in each occurrence independently is alkyl, -alkylaryl,        cycloalkyl, heterocyclyl, aryl or heteroaryl, each of which may        optionally be substituted;    -   R⁴ and R⁵ in each occurrence independently are hydrogen, C₁-C₆        alkyl or C₃-C₆ cycloalkyl, or R⁴ and R⁵ and the carbon atom to        which they are connected form a C₃-C₆ cycloalkyl ring;    -   R⁶ in each occurrence independently is hydrogen, R³, —C(═O)R³,        —C(═O)OR³ or —C(═O)NR⁹R¹⁰; or    -   R⁶ and R⁴ or R⁵, together with the atoms to which they are        connected, form a heterocyclic ring;

R⁹ and R¹⁰ in each occurrence independently are hydrogen, alkyl,-alkylaryl, cycloalkyl, heterocyclyl, aryl or heteroaryl; or

-   -   R⁹ and R¹⁰ and the nitrogen atom to which they are connected        form a heterocyclic or heteroaryl ring;    -   j in each occurrence independently is an integer from 0 to 4;        and    -   m in each occurrence independently is an integer from 1 to 10;        or a pharmaceutically acceptable salt, solvate, hydrate,        clathrate, polymorph or stereoisomer thereof, with the proviso        that:

both R¹ and R² are not hydrogen;

neither —OR¹ nor —OR² forms an acetate;

neither —OR¹ nor —OR² forms a substituted cyclohexane-ester; and

neither —OR¹ nor —OR² forms an ester with or of an amino acid (protectedor unprotected), a peptide or a protein.

2. The compound of embodiment 1, wherein R³ in

is not alkyl substituted with a nitrogen-containing group, or notcycloalkyl substituted with a carbonyl-containing group.3. The compound of embodiment 1, wherein neither the alkyl nor thecycloalkyl group, or none of the alkyl, -alkylaryl, cycloalkyl,heterocyclyl, aryl or heteroaryl group, of R³ in

is substituted.4. The compound of any one of the preceding embodiments, wherein j ineach occurrence independently is 0, 1 or 2.5. The compound of any one of the preceding embodiments, wherein m ineach occurrence independently is an integer from 1 to 6.6. The compound of any one of the preceding embodiments, wherein R¹ andR² independently are

and wherein:

R⁴, R⁵, R⁶ and m are as defined above; and

k in each occurrence independently is an integer from 1 to 9.

7. The compound of embodiment 6, wherein k in each occurrenceindependently is an integer from 1 to 5.8. The compound of any one of the preceding embodiments, wherein:

R³ in each occurrence independently is C₁-C₆ alkyl;

R⁴ and R⁵ in each occurrence independently are hydrogen or C₁-C₃ alkyl,or R⁴ and R⁵ and the carbon atom to which they are connected form acyclopropyl ring;

R⁶ in each occurrence independently is hydrogen or R³;

j in each occurrence independently is 0 or 1; and

m in each occurrence independently is 1 or 2.

9. The compound of embodiment 8, wherein:

R³ in each occurrence independently is methyl, ethyl, propyl, isopropyl,butyl, iso-butyl, sec-butyl or tert-butyl;

R⁴ and R⁵ in each occurrence independently are hydrogen, methyl, ethyl,propyl or isopropyl;

R⁶ in each occurrence independently is hydrogen or R³;

j is 0; and

m is 1.

10. The compound of any one of the preceding embodiments, wherein R¹ andR² independently are selected from the group consisting of: hydrogen,

with the proviso that both R¹ and R² are not hydrogen.

11. The compound of embodiment 10, wherein R¹ and R² independently areselected from the group consisting of:

hydrogen,

with the proviso that both R¹ and R² are not hydrogen.

12. The compound of any one of the preceding embodiments, wherein both—OR¹ and —OR² are derivatized [Formula (Ic)], optionally with the samegroup.13. The compound of any one of embodiments 1 to 11, wherein both —OR¹and —OR² are not derivatized.14. The compound of embodiment 13, wherein R² is hydrogen and —OR¹ isderivatized [Formula (Ia)].15. The compound of embodiment 13, wherein RI is hydrogen and —OR² isderivatized [Formula (Ib)].16. The compound of any one of the preceding embodiments, which isselected from the group consisting of:

and pharmaceutically acceptable salts, solvates, hydrates, clathrates,polymorphs and stereoisomers thereof.17. A compound selected from the group consisting of:

and pharmaceutically acceptable salts, solvates, hydrates, clathrates,polymorphs and stereoisomers thereof.18. A compound of Formula (II):

wherein:

—O—Z—CO₂H is

—O-heteroalkyl-CO₂H, —O-cyclyl-CO₂H, —O—CH₂-cyclyl-CO₂H,—O-cyclyl-CH₂—CO₂H, or —O—CH₂-cyclyl-CH₂—CO₂H, each of which mayoptionally be substituted,

wherein:

-   -   cyclyl- is -cycloalkyl-, -heterocyclyl-, -aryl- or -heteroaryl-;    -   R⁷ and R⁸ in each occurrence independently are hydrogen, C₁-C₆        alkyl or C₃-C₆ cycloalkyl, or R⁷ and R⁸ and the carbon atom to        which they are connected form a C₃-C₆ cycloalkyl ring; and    -   n is an integer from 1 to 10;        or a pharmaceutically acceptable salt, solvate, hydrate,        clathrate, polymorph or stereoisomer thereof, with the proviso        that:

—O—Z—CO₂H is not

and

—O—Z—CO₂H does not contain a sugar moiety.

19. The compound of embodiment 18, wherein n is an integer from 1 to 6.20. The compound of embodiment 18, wherein —O—Z—CO₂H does not contain a-heterocyclyl- group, or a substituted -heterocyclyl- group.21. The compound of embodiment 18, wherein —O—Z—CO₂H is

and wherein:

R⁷ and R⁸ are as defined above;

p is an integer from 1 to 9; and

q is an integer from 0 to 8;

with the proviso that —O—Z—CO₂H is not

22. The compound of embodiment 21, wherein p is an integer from 1 to 5,and q is an integer from 0 to 4.23. The compound of embodiment 21 or 22, wherein both R⁷ and R⁸ arehydrogen, and p is an integer from 1 to 5 or from 1 to 3 (or eachoccurrence of R⁷ and R⁸ is hydrogen, and q is an integer from 0 to 4 orfrom 0 to 2).24. The compound of embodiment 21 or 22, wherein —O—Z—CO₂H is

and p is 2, 3, 4 or 5.25. The compound of embodiment 18, wherein —O—Z—CO₂H is—O-heteroalkyl-CO₂H, and —O-heteroalkyl-CO₂H is selected from the groupconsisting of:

wherein r is each of 1, 2 and 3.26. The compound of embodiment 25, wherein —O—Z—CO₂H is

and r is 1, 2 or 3.27. The compound of embodiment 18, wherein —O—Z—CO₂H is—O-cycloalkyl-CO₂H, —O—CH₂-cycloalkyl-CO₂H, —O-cycloalkyl-CH₂—CO₂H, or—O—CH₂-cycloalkyl-CH₂—CO₂H, and for each of the preceding moieties-cycloalkyl- is:

1,2-cyclopropyl (cis or trans); or

1,3-cyclobutyl (cis or trans) or 1,2-cyclobutyl (cis or trans); or

1,3-cyclopentyl (cis or trans) or 1,2-cyclopentyl (cis or trans); or

1,4-cyclohexyl (cis or trans), 1,3-cyclohexyl (cis or trans), or1,2-cyclohexyl (cis or trans).

28. The compound of embodiment 27, wherein —O—Z—CO₂H is selected fromthe group consisting of:

29. The compound of any one of embodiments 18 to 28, which is selectedfrom the group consisting of:

and pharmaceutically acceptable salts, solvates, hydrates, clathrates,polymorphs and stereoisomers thereof.30. The compound of embodiment 29, which is selected from the groupconsisting of:

and pharmaceutically acceptable salts, solvates, hydrates, clathrates,polymorphs and stereoisomers thereof.31. A compound selected from the group consisting of:

and pharmaceutically acceptable salts, solvates, hydrates, clathrates,polymorphs and stereoisomers thereof.32. The compound of embodiment 31, which is selected from the groupconsisting of:

and pharmaceutically acceptable salts, solvates, hydrates, clathrates,polymorphs and stereoisomers thereof.33. A pharmaceutical composition comprising a compound of any one ofembodiments 1 to 32, or a pharmaceutically acceptable salt, solvate,hydrate, clathrate, polymorph or stereoisomer thereof, and one or morepharmaceutically acceptable excipients or carriers.34. The composition of embodiment 33, wherein the compound is a compoundof embodiment 17 or 31, or a pharmaceutically acceptable salt, solvate,hydrate, clathrate, polymorph or stereoisomer thereof.35. The composition of embodiment 34, wherein the compound is a compoundof embodiment 17 or 32, or a pharmaceutically acceptable salt, solvate,hydrate, clathrate, polymorph or stereoisomer thereof.36. The composition of any one of embodiments 33 to 35, which isconfigured for transdermal delivery of the compound.37. The composition of embodiment 36, which is configured as atransdermal patch.38. A method of treating a medical condition responsive to treatmentwith treprostinil, comprising administering to a subject in need oftreatment a therapeutically effective amount of a compound of any one ofembodiments 1 to 32, or a pharmaceutically acceptable salt, solvate,hydrate, clathrate, polymorph or stereoisomer thereof.39. The method of embodiment 38, wherein the medical condition isselected from the group consisting of pulmonary hypertension, pulmonaryfibrosis, peripheral ischemic lesions on the skin (e.g., those caused byscleroderma, Buerger's disease, Raynaud's disease, Raynaud's phenomenonand systemic sclerosis), critical limb ischemia, diabetic neuropathicfoot ulcer, kidney malfunction and failure, peripheral vascular disease,atherogenesis (e.g., atherosclerosis), congestive heart failure, tumors,cancers, and pain associated with each of the preceding conditions.40. The method of embodiment 39, wherein the medical condition ispulmonary hypertension.41. The method of embodiment 40, wherein the medical condition ispulmonary arterial hypertension.42. The method of any one of embodiments 38 to 41, wherein the compoundis a compound of embodiment 17 or 31, or a pharmaceutically acceptablesalt, solvate, hydrate, clathrate, polymorph or stereoisomer thereof.43. The method of embodiment 42, wherein the compound is a compound ofembodiment 17 or 32, or a pharmaceutically acceptable salt, solvate,hydrate, clathrate, polymorph or stereoisomer thereof.44. The method of any one of embodiments 38 to 43, wherein the route ofadministration of the compound comprises oral, parenteral (e.g.,intradermal, subcutaneous, intramuscular, intravascular, intravenous,intraarterial, intramedullary or intrathecal), intracavitary,intraperitoneal, or topical (e.g., dermal/epicutaneous, transdermal,mucosal, transmucosal, intranasal [e.g., by nasal spray or drop],intraocular [e.g., by eye drop], pulmonary [e.g., by inhalation],buccal, sublingual, rectal or vaginal), or any combination thereof.45. The method of embodiment 44, wherein the compound is administeredtransdermally (e.g., via a transdermal patch).46. The method of any one of embodiments 38 to 45, wherein:

the medical condition is pulmonary arterial hypertension;

the compound is a compound of embodiment 17 or 31, or a pharmaceuticallyacceptable salt, solvate, hydrate, clathrate, polymorph or stereoisomerthereof; and

the compound is administered transdermally (e.g., via a transdermalpatch).

47. The method of any one of embodiments 38 to 46, further comprisingadministering an additional therapeutic agent.48. The method of embodiment 47, wherein the additional therapeuticagent comprises a vasoactive agent, a diuretic or an anticoagulant, orany combination thereof.49. A kit comprising:

a compound of any one of embodiments 1 to 32, or a pharmaceuticallyacceptable salt, solvate, hydrate, clathrate, polymorph or stereoisomerthereof; and

instructions for administering the compound to treat a medical conditionresponsive to treatment with treprostinil.

50. The kit of embodiment 49, wherein the compound is contained orincorporated in a device or system configured for transdermal delivery(e.g., a transdermal patch).51. The kit of embodiment 49 or 50, wherein the medical condition ispulmonary hypertension (e.g., pulmonary arterial hypertension).

X. Examples

The following examples are intended only to illustrate the disclosure.Other procedures, methodologies, assays, conditions and reagents mayalternatively be used as appropriate.

Biological Assays of Treprostinil Derivatives Example 1. StabilityAssays of Treprostinil Derivatives

The following three stability assays were conducted on treprostinilderivatives, with the results shown in Table 1.

(Test 1)

Human liver microsomal stability assay was conducted by incubating 0.5μM test compound at 37° C. for up to 45 minutes in 50 mM potassiumphosphate buffer (pH 7.4) containing 0.5 mg of microsomal protein and 50μL of NADPH-generating system (7.8 mg of glucose 6-phosphate, 1.7 mg ofNADPH and 6 U of glucose 6-phosphate dehydrogenase per mL in 2% w/v ofsodium bicarbonate). At 0, 5, 15, 30 and 45 min, an aliquot was takenand quenched with internal standard-containing stop solution. Noco-factor controls at 45 min were prepared. After incubation, thesamples were analyzed by LC-MS/MS. Peak area ratios of analyte tointernal standard were used to calculate the intrinsic clearance. Theintrinsic clearance (CL_(int)) was determined from the first-orderelimination constant by non-linear regression. Formation of the activedrug treprostinil (Compound A) over the time course was monitored byLC-MS/MS analysis.

(Test 2)

Human plasma stability assay was conducted by incubating 0.5 μM testcompound at 37° C. for up to 120 min in heparinated human plasma. At 0,5, 15, 30, 60, 120 and 240 min, an aliquot was taken and quenched withinternal standard-containing stop solution. After incubation, thesamples were analyzed by LC-MS/MS. Peak area ratios of analyte tointernal standard were used to calculate the half-life. Formation of theactive drug Compound A over the time course was monitored by LC-MS/MSanalysis.

(Test 3)

Human skin homogenate stability assay was conducted in a similar manneras the human liver microsomal stability assay, by incubating 0.5 μM testcompound at 37° C. for up to 45 min in 50 mM potassium phosphate buffer(pH 7.4) containing 0.5 mg of human skin homogenate protein and 50 μL ofNADPH-generating system (7.8 mg of glucose 6-phosphate, 1.7 mg of NADPHand 6 U of glucose 6-phosphate dehydrogenase per mL in 2% w/v of sodiumbicarbonate). At 0, 5, 15, 30 and 45 min, an aliquot was taken andquenched with internal standard-containing stop solution. No co-factorcontrols at 45 min were prepared. After incubation, the samples wereanalyzed by LC-MS/MS. Peak area ratios of analyte to internal standardwere used to calculate the intrinsic clearance. The intrinsic clearance(CL_(int)) was determined from the first-order elimination constant bynon-linear regression. Formation of the active drug Compound A over thetime course was monitored by LC-MS/MS analysis.

Results (half-life) of the three stability assays described above areshown in Table 1. For Table 1, the code for the half-life of the testcompounds in the assays is:

A=<15 min

B=15-30 min

C=31-60 min

D=>60 min

TABLE 1 Cmpd MW m/z Test 1 Test 2 Test 3 No. (g/mol) [M + Na]⁺ T_(1/2)T_(1/2) T_(1/2) Test 4 A 390 413 +++ +++ Ia-1 446 469 A D D + + + Ia-3474 497 A D D + + Ia-7 448 471 A D D Ia-8 462 485 A D D +++ +++ ++ Ia-9476 499 A D D Ia-10 448 471 A D D ++ ++ Ia-11 462 485 A D D ++ ++ ++Ia-14 478 501 C D D +++ +++ +++ Ib-8 462 485 A D D Ib-10 448 471 A D DII-1 448 471 C D D +++ ++ II-2 462 485 C D D ++++ ++++ ++++ II-4 462 485B D D +++ +++

Example 2. Skin Flux Assay of Treprostinil Derivatives

(Test 4

) A skin flux assay was performed using a vertical Franz diffusion cellhaving a diffusion area of 0.64 cm² and a volume of 7.5 mL. The assaywas conducted at 32° C. with continuous stirring. Heat-separated humancadaver epidermis was used in the assay, the epidermis being stored at−20° C. after the heat stripping procedure. The human epidermis wasthawed prior to being mounted on the diffusion cell. A test compound wasapplied on the skin, and the diffusion cell was closed by screw-cap. Atvarious time intervals, whole medium or receptor medium was replaced byfresh medium. Part of the collected medium was used to calculate theskin flux of the test compound. The skin flux of various test compoundswas evaluated using human epidermis from different donors. N=4replicates were performed for each test compound tested on humanepidermis from a particular donor.

Results of the skin flux assay are shown in Table 1 above. For Table 1,the code for the average skin flux of the test compounds tested on humanepidermis from a particular donor is:

+=low to moderate skin flux

=medium skin flux

+++=high skin flux

++++=very high skin flux

Synthesis of Treprostinil Derivatives

Representative syntheses of compounds of Formulas (I) and (II) are shownbelow.

Synthesis of{2-hydroxy-1-[3-(tetrahydropyran-2-yloxy)octyl]-2,3,3a,4,9,9a-hexahydro-1H-cyclopenta[b]naphthalen-5-yloxy}aceticAcid Benzyl Ester (Compound C)

A solution of{2-hydroxy-1-[3-(tetrahydropyran-2-yloxy)octyl]-2,3,3a,4,9,9a-hexahydro-1H-cyclopenta[b]naphthalen-5-yloxy}acetic acid (Compound B) (2 g, 4.21mmol), benzyl alcohol (2.47 g, 22.9 mmol) and triethylamine (7.2 g, 71.3mmol) in dichloromethane (DCM) (20 mL) was treated withbis(2-oxo-3-oxazolidinyl)phosphinic chloride (BOP-Cl) (7.8 g, 30.7 mmol)at 0° C. and stirred at room temperature (RT) for 2 hr. The reactionmixture was diluted with methyl-tert-butyl ether (MTBE) and washed withwater and then brine, dried over sodium sulfate and concentrated undervacuum. The residue was purified by silica gel chromatography to provideCompound C. MS: m/z 587 [M+Na]⁺

Example 3. Synthesis of[1-(3-hydroxyoctyl)-2-(2-methoxyacetoxy)-2,3,3a,4,9,9a-hexahydro-1H-cyclopenta[b]naphthalen-5-yloxy]aceticAcid (Compound Ia-8)

A solution of Compound C (90 mg, 0.15 mmol), NEt₃ (70 μL, 0.5 mmol) and4-dimethylaminopyridine (DMAP) (1 crystal) in DCM (2 mL) was treatedwith methoxyacetyl chloride (21 μL, 0.22 mmol) and stirred at RT for 12hr under nitrogen. The reaction mixture was diluted with MTBE and washedwith water and then brine, dried over sodium sulfate and concentratedunder vacuum. The residue was purified by silica gel chromatography. TheTHP-protected methoxyacetate was dissolved in MeOH (4 mL), treated withpyridinium para-toluene-sulfonate (PPTS) (catalytic) and stirred at 50°C. for 2 hr. The reaction mixture was concentrated, and the residue wasdissolved in MTBE (20 mL) and washed with water and then brine to yieldcrude THP-deprotected methoxyacetate. The crude product was taken indioxane (5 mL) along with 10% Pd/C (18 mg) and hydrogenated under ahydrogen atmosphere to yield crude Compound Ia-8 (64 mg) as an oil. MS:m/z 485 [M+Na]⁺

The following compounds were synthesized using similar procedures asabove:

Example 4. Synthesis of[2-(2-hydroxyacetoxy)-1-(3-hydroxyoctyl)-2,3,3a,4,9,9a-hexahydro-1H-cyclopenta[b]naphthalen-5-yloxy]aceticAcid (Compound Ia-7)

A solution of Compound C (100 mg, 0.177 mmol), NEt₃ (77 μL, 0.55 mmol)and DMAP (1 crystal) in DCM (2 mL) was treated with benzyloxyacetylchloride (65 mg, 0.22 mmol) and stirred at RT for 12 hr under nitrogen.The reaction mixture was diluted with MTBE and washed with water andthen brine, dried over sodium sulfate and concentrated under vacuum. Theresidue was purified by silica gel chromatography. The THP-protectedbenzyloxyacetate was dissolved in MeOH (4 mL), treated with PPTS(catalytic) and stirred at 50° C. for 2 hr. The reaction mixture wasconcentrated, and the residue was dissolved in MTBE (20 mL) and washedwith water and then brine to yield crude THP-deprotectedbenzyloxyacetate. The crude product was taken in dioxane (5 mL) alongwith 10% Pd/C (24 mg) and hydrogenated under a hydrogen atmosphere toyield crude Compound Ia-7 (56 mg) as an oil. MS: m/z 471 [M+Na]⁺

Example 5. Synthesis of[1-(3-hydroxyoctyl)-2-methoxycarbonyloxy-2,3,3a,4,9,9a-hexahydro-1H-cyclopenta[b]naphthalen-5-yloxy]aceticAcid (Compound Ia-10)

A solution of Compound C (160 mg, 0.28 mmol) and NEt₃ (798 μL, 2.8 mmol)in DCM (2 mL) was treated with phosgene solution (906 μL, 1.4 mmol, 0.5M in toluene) at 0° C., and the resulting mixture was stirred at 0° C.for 0.5 hr under nitrogen. The reaction mixture was then added to MeOH(2 mL) at 0° C. and stirred for an additional 1 hr. The solvent wasremoved, and the residue was purified by silica gel chromatography. TheTHP-protected methylcarbonate was dissolved in MeOH (4 mL), treated withPPTS (catalytic) and stirred at 50° C. for 2 hr. The reaction mixturewas concentrated, and the residue was dissolved in MTBE (20 mL) andwashed with water and then brine to yield crude THP-deprotectedmethylcarbonate. The crude product was taken in dioxane (5 mL) alongwith 10% Pd/C (28 mg) and hydrogenated under a hydrogen atmosphere toyield crude Compound Ia-10 (83 mg) as an oil. MS: m/z 471 [M+Na]⁺

The following compound was synthesized using similar procedures asabove:

Synthesis of[2-benzyloxycarbonyloxy-1-(3-hydroxyoctyl)-2,3,3a,4,9,9a-hexahydro-1H-cyclopenta[b]naphthalen-5-yloxy]aceticAcid Benzyl Ester (Compound D)

A solution of Compound C (100 mg, 0.177 mmol), NEt₃ (77 μL, 0.55 mmol)and DMAP (1 crystal) in DCM (2 mL) was treated withN-(benzyloxycarbonyloxy)succinimide (84 mg, 0.34 mmol) and stirred at RTfor 24 hr under nitrogen. The reaction mixture was diluted with MTBE andwashed with water and then brine, dried over sodium sulfate andconcentrated under vacuum. The residue was purified by silica gelchromatography. The benzylcarbonate was dissolved in MeOH (4 mL),treated with PPTS (catalytic) and stirred at 50° C. for 2 hr. Thereaction mixture was concentrated, and the residue was dissolved in MTBE(20 mL) and washed with water and then brine to yield crude Compound D(110 mg) as an oil.

Example 6. Synthesis of{2-hydroxy-1-[3-(2-methoxyacetoxy)octyl]-2,3,3a,4,9,9a-hexahydro-1H-cyclopenta[b]naphthalen-5-yloxy}aceticAcid (Compound Ib-8)

A solution of Compound D (70 mg, 0.11 mmol), NEt₃ (75 μL, 0.52 mmol) andDMAP (1 crystal) in DCM (2 mL) was treated with methoxyacetyl chloride(21 μL, 0.22 mmol) and stirred at 0° C. for 1 hr under nitrogen. Thereaction mixture was diluted with MTBE and washed with water and thenbrine, dried over sodium sulfate and concentrated under vacuum. Theresidue was purified by silica gel chromatography. The methoxyacetatewas taken in dioxane (5 mL) along with 10% Pd/C (16 mg) and hydrogenatedunder a hydrogen atmosphere to yield crude Compound Ib-8 (43 mg) as anoil. MS: m/z 485 [M+Na]⁺

The following compounds were synthesized using similar procedures asabove:

Example 7. Synthesis of3-{2-[2-hydroxy-1-(3-hydroxyoctyl)-2,3,3a,4,9,9a-hexahydro-1H-cyclopenta[b]naphthalen-5-yloxy]acetoxy}propionicAcid (Compound 11-4)

To a solution of Compound B (120 mg, 0.25 mmol), benzyl3-hydroxypropionate (54 mg, 0.30 mmol) and trimethylamine (140 μL, 1.0mmol) in DCM (4 mL) was added BOP-Cl (95 mg, 0.38 mmol). The reactionmixture was stirred at RT for 16 hr under nitrogen, diluted with MTBE,washed with brine, dried over sodium sulfate, and concentrated to an oilthat was purified by silica gel chromatography. A solution of theTHP-protected diester in ethanol (4 mL) was treated with PPTS (50 mg),stirred at 50° C. for 4 hr, and concentrated to an oil that was purifiedby silica gel chromatography. A solution of the THP-deprotected diesterin dioxane (5 mL) was treated with wet 5% Pd/C (20 mg) and stirred for24 hr under a balloon of hydrogen. The reaction mixture was filtered andconcentrated to give crude Compound 11-4. MS: m/z 485 [M+Na]⁺

The following compounds were synthesized using similar procedures asabove:

It is understood that, while particular embodiments have beenillustrated and described, various modifications may be made thereto andare contemplated herein. It is also understood that the disclosure isnot limited by the specific examples provided herein. The descriptionand illustration of embodiments and examples of the disclosure hereinare not intended to be construed in a limiting sense. It is furtherunderstood that all aspects of the disclosure are not limited to thespecific depictions, configurations or relative proportions set forthherein, which may depend upon a variety of conditions and variables.Various modifications and variations in form and detail of theembodiments and examples of the disclosure will be apparent to a personskilled in the art. It is therefore contemplated that the disclosurealso covers any and all such modifications, variations and equivalents.

1-20. (canceled)
 21. A pharmaceutical composition comprising one or morepharmaceutically acceptable excipients or carriers and a compoundselected from the group consisting of:

and pharmaceutically acceptable salts, solvates, hydrates, clathrates,polymorphs and stereoisomers thereof.
 22. The pharmaceutical compositionof claim 21, which is formulated for transdermal delivery of thecompound.
 23. The pharmaceutical composition of claim 22, which isconfigured as a transdermal patch.
 24. A method of treating a medicalcondition responsive to treatment with treprostinil, comprisingadministering to a subject in need of treatment a therapeuticallyeffective amount of a compound selected from the group consisting of:

and pharmaceutically acceptable salts, solvates, hydrates, clathrates,polymorphs and stereoisomers thereof.
 25. The method of claim 24,wherein the medical condition is selected from the group consisting ofpulmonary hypertension, pulmonary fibrosis, ischemic diseases,peripheral vascular disease, peripheral ischemic lesions on the skin,critical limb ischemia, heart failure, atherogenesis, inflammatorydiseases, diabetic neuropathic foot ulcer, kidney malfunction andfailure, tumors, cancers, and pain associated with each of the precedingconditions.
 26. The method of claim 25, wherein the medical condition ispulmonary hypertension.
 27. The method of claim 26, wherein the medicalcondition is pulmonary arterial hypertension.
 28. The method of claim24, wherein the compound is administered topically.
 29. The method ofclaim 28, wherein the compound is administered transdermally.
 30. Themethod of claim 29, wherein the compound is administered via atransdermal patch.
 31. The method of claim 28, wherein the compound isadministered pulmonarily by oral inhalation.
 32. The method of claim 24,wherein the compound is administered orally.
 33. The method of claim 24,wherein the compound is administered parenterally.
 34. The method ofclaim 33, wherein the compound is administered subcutaneously orintravenously.
 35. The method of claim 24, further comprisingadministering an additional therapeutic agent.
 36. The method of claim35, wherein the additional therapeutic agent comprises a vasoactiveagent, a diuretic, an anticoagulant or a cardiac glycoside, or anycombination thereof.